US3128712A - Canned motor pump - Google Patents

Canned motor pump Download PDF

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Publication number
US3128712A
US3128712A US129099A US12909961A US3128712A US 3128712 A US3128712 A US 3128712A US 129099 A US129099 A US 129099A US 12909961 A US12909961 A US 12909961A US 3128712 A US3128712 A US 3128712A
Authority
US
United States
Prior art keywords
rotor
shaft
liquid
motor
chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US129099A
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English (en)
Inventor
Leonard H Sence
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Allis Chalmers Corp
Original Assignee
Allis Chalmers Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Allis Chalmers Corp filed Critical Allis Chalmers Corp
Priority to US129099A priority Critical patent/US3128712A/en
Priority to GB28482/62A priority patent/GB935585A/en
Priority to CH924662A priority patent/CH383170A/fr
Priority to DE19621453711 priority patent/DE1453711A1/de
Priority to BE621060A priority patent/BE621060A/fr
Application granted granted Critical
Publication of US3128712A publication Critical patent/US3128712A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/02—Units comprising pumps and their driving means
    • F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/0606—Canned motor pumps
    • F04D13/0613—Special connection between the rotor compartments
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K5/00—Casings; Enclosures; Supports
    • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
    • H02K5/12—Casings or enclosures characterised by the shape, form or construction thereof specially adapted for operating in liquid or gas
    • H02K5/128—Casings or enclosures characterised by the shape, form or construction thereof specially adapted for operating in liquid or gas using air-gap sleeves or air-gap discs

Definitions

  • This invention relates generally to canned motors. More specifically this invention relates to canned motor pump units having improved efliciency.
  • the canned motor is a type of motor having a cylindrical sleeve positioned between the rotor and stator of the motor to form a rotor chamber separated from the stator.
  • a motor pump unit the can is sealed at one end to the motor housing and at the other end to the bearing housing intermediate the motor and the pump. Fluid leaking from the pump along the shaft flows into the can and then through appropriate conduits back to the suction side of the pump.
  • this type of unit is known in the art as the sealless motor pump unit.
  • the canned motor pump unit is ideal for many applications such as pumping highly explosive, precious or toxic liquids.
  • these units especially when operating at high speeds and pumping dense liquids the power loss due to the rotor rotating in a chamber full of liquid are exceedingly high.
  • the power loss due to the rotor rotating in a chamber full of liquid are exceedingly high.
  • more than 50% of the power can be consumed in rotating the rotor rather than in pumping the liquid.
  • the pump of this invention overcomes the problem mentioned above by controlling the volume of liquid flowing into the rotor chamber so that there is a minimum of liquid in the chamber. This is accomplished by restricting the inlets into the rotor chamber and balancing the pressure across the rotor chamber so that there is no pressure differential or at most an insignificant pressure differential. The very small amount of liquid that then flows into the rotor chamber is heated by the heat from the motor and hence vaporizes. The vapor expands and then exerts a slightly greater pressure than the liquid outside of the rotor chamber. Therefore, no more liquid flows into the rotor chamber and the rotor operates in a vapor with a minimum of power loss.
  • Another object of this invention is'to provide a new and improved motor pump unit.
  • Another object of this invention is to provide a new and improved motor pump unit having increased efficiency.
  • the figure is a cross sectional view of a motor pump unit of this invention.
  • the invention is illustrated in con connection with a motor pump unit 10.
  • the motor pump unit comprises generally a motor 11 driving a shaft 12 which is in turn operatively connected to the impeller 13 of a centrifugal pump 14.
  • the motor 11 comprises an annular housing or yoke 16 surrounding a stator 17 which in turn surrounds a rotor 18 mounted on the shaft 12.
  • a pair of annular end covers 19 are connected to the yoke and form the stator chamber.
  • a cylindrical stator can 20 is positioned intermediate the rotor 13 and the stator 17 to form a rotor chamber 21 in which the rotor rotates. The can 20 is sealed at both ends to hydraulically seal the stator from the rotor chamber.
  • This 2 can be accomplished in any suitable way but as illustrated an O-ring 22 is compressed between each end of the can 20 and the associated member that closes the rotor chamber of the motor. In some applications it may also be desirable to encase the rotor in a can 24 to protect it from the liquid in the rotor chamber 21.
  • a centrifugal pump impeller 13 is mounted on the extended end of the shaft 12.
  • the impeller 13 is surrounded by a suitable pump casing 26 having an axial inlet 27 and a radially spaced discharge volute 28 that are aligned with the intake and outlet, respectively, of the impeller.
  • a hearing housing 30 surrounds the shaft 12 and is positioned intermediate the motor 11 and the pump 14.
  • the bearing housing 39 is connected to the pump casing 26 by bolts 31 and forms the back cover plate of the pump.
  • the other end of the bearing housing 30 is connected to the end cover 19 of the motor housing by bolts 32 and closes one end of the motor chamber 21. This portion of the bearing housing cooperates with the flared portion of can 29 to compress O-ring 22 therebetween.
  • a second bearing housing 35 surrounds the end of shaft 12 on the other side of the rotor 18.
  • the bearing housing is shown as being bellshaped and is connected to an end cover 19 of the motor housing 16 by suitable bolts 36 and closes the other end of the rotor chamber 21.
  • Suitable bearings such as the illustrated sleeve bearings 33, 39 are mounted on the radially inner surface of the bearing housings 30, 35.
  • the bearings surround and support the rotating shaft 12 in the usual manner.
  • These bearings are shown as being lubricated by the liquid being pumped, but may be lubricated from a separate source of lubricant if desired.
  • Suitable conduits are provided for bringing lubricant under pressure into the bearing housings.
  • this lubricant is the liquid being pumped and is brought into the bearings from the discharge side of the centrifugal pump.
  • a conduit 40 is formed in the first bearing housing 30 and connects the discharge side of the pump 14 with the inboard side of the sleeve bearing 38.
  • Pipe 41 connects the discharge nozzle 28a of the pump 14 to the second bearing housing 35.
  • the liquid entering the bearing housing 35 is used to lubricate the bearing 39.
  • some liquid leaks behind the impeller and along the shaft to the bearing 33 intermediate the pump and the motor to help lubricate the bearing.
  • the unit 10 is also provided with means for draining the liquid used to lubricate the bearings back to the intake side of the pump so that none of the liquid leaks out of the system.
  • the shaft 12 has an axial conduit 44 extending almost the entire length of the shaft and has radial holes 45 in communication with the conduit 44 and the annular spaces 46 adjacent the bearings being lubricated. In this mannor the liquid flows around the bearings for lubrication and then into the conduit 44 in the shaft 12 and from there to the low pressure intake side of the pump impeller 13;
  • the primary concern in motor pump units of this type is to eliminate leakage of liquid out of the hydraulic system.
  • it is extremely difiicult to provide a prefect seal in the pumping unit especially between a rotating member such as the shaft 12 and a stationary member such as the rear cover of the pump casing.
  • a rotating member such as the shaft 12
  • a stationary member such as the rear cover of the pump casing.
  • leakage from the system is prevented by allowing the liquid to flow behind the impeller along the shaft past the stationary member and then back through the shaft to the inlet side of the impeller.
  • the liquid that leaks along the shaft serves to lubricate the bearings.
  • additional liquid may be required to lubricate the bearings, especially if the unit is provided with a second bearing on the outboard side of the motor.
  • the extra liquid is obtained from the high pressure liquid in the discharge volute of the pump. This liquid is directed to the bearings as described above.
  • the extra liquid for lubricating the bearings flows near the rotor chamber and hence complicates the problem of limiting the amount of liquid entering the rotor chamber 21.
  • the flow into the rotor chamber can be controlled by reducing the pressure of the liquid lubricating the bearings and controlling the pressure drop across the rotor chamber so that it becomes a negligible factor. This can be accomplished by providing suitable control valves such as valve 48 or other pressure reducing means in the conduits between the discharge side of the pump and the bearings.
  • bushings 50 are mounted on the shaft 12 intermediate the bearings 38, 39 being lubricated and the rotor chamber 21. These bushings 50 are mounted on the shaft and positioned to form with the bearing housings 30, 35 a close clearance 51 in the hydraulic path between the bearings 38, 39 and the interior of the rotor chamber.
  • the clearances 51 are relatively long and have a very small radial space to effect a significant pressure drop across the bushing and retard the flow of liquid into the rotor chamber.
  • bushings are used on both ends of the rotor to minimize the pressure drop across the rotor chamber. These bushings also serve as a flame path bushing to confine, retard and extinguish any flames emanating from an explosion within the rotor chambers. Use of bushings for quenching flames is Well known in the motor art.
  • one hearing may be suificient to support the shaft. If only a single bearing is used, means are provided for limiting the flow of liquid into the rotor chamber. Suchcontrol means would be similar to the bushing 59 between the motor and the pump. Furthermore, a return passage for any excess liquid that might be in the rotor chamber would also, be provided. The return passage would be fronf the rear of the rotor chamber through the shaft back to the intake side of the impeller. Means such as a flame path bushing will be provided in the return passage for controlling the flow of liquid through the rotor chamber.
  • liquid is tapped from the discharge nozzle 28a of the pump and directed through pipe 41 and control valve 48 into bearing housing 35 at the other'end of the unit.
  • the liquid enters the bearing housing and flows around the shaft 12 to lubricate the bearing 39.
  • the end of the shaft surrounded by the bearing housing 35 is closed to force the liquid entering the housing to flow around the shaft and lubricate the bearing 39.
  • the liquid has passed the bearing, a portion of it tries to flow past the bushing 5t tl rough the clearance 51 into the rotor chamber 21.
  • the remainder of the liquid flows through radial holes 45 into the hollow portion of the shaft and then back through the shaft to the inlet side of the pump.
  • a motor pump unit comprising: an annular stator, a motor housing surrounding said stator, a rotor mounted within said stator, a cylindrical can positioned intermedi-' ate said rotor and said stator to form a chamber in which said rotor rotates, a shaft connected to said rotor and extending out of said chamber, an impeller mounted on the extended end of said shaft, a pump casing surrounding said impeller, a bearing housing surrounding said shaft intermediate said rotor and said impeller, means on said shaft positioned to cooperate with said bearing housing to form such a close clearance therebetween as to limit the amount of liquid entering said can to such a small amount that during operation, said liquid will be completely vaporized by the heat generated by the motor. 2.
  • a motor pump unit comprising: an annular stator, a motor housing surrounding said stator, a rotor mounted within said stator, a cylindrical can positioned intermediate said rotor and said stator to form a chamber in which said rotor rotates, a shaft connected to said rotor and extending out of said chamber, an impeller mounted on the extended end of said shaft, a pump casing surrounding said impeller, said shaft between said rotor and said impeller cooperating with said casing to form such a close clearance therebetween as to limit the amount of liquid entering said can to such a small amount that during operation, said liquid will be completely vaporized by the heat generated by the motor. 3.
  • a motor pump unit comprising: an annular stator, a motor housing surrounding said stator, a rotor mounted Within said stator, a cylindrical can positioned intermediate said rotor and said stator to form a chamber in which said rotor rotates, a shaft connected to said rotor and extending out of said chamber, an impeller mounted on the extended end of said shaft, a pump casing surrounding said impeller, means on said shaft between said rotor and said impeller cooperating With said housing to form such a close clearance therebetween as to limit the amount of liquid entering said can to such a small amount that during operation, said liquid will be completely vaporized by the heat generated by the motor.
  • a motor pump unit comprising: an annular stator, a motor housing surrounding said stator, a rotor mounted Within said stator, a cylindrical can positioned intermediate said rotor and said stator to form a chamber in which said rotor rotates, a shaft connected to said rotor and extending out of said chamber, an impeller mounted on the extended end of said shaft, a pump casing surrounding said impeller, a bearing housing surrounding said shaft intermediate said rotor and said impeller, means on said shaft positioned to cooperate with said bearing housing to form such a close clearance therebetween as to limit the amount of liquid entering said rotor chamber to such a small amount that during operation, said liquid Will be completely vaporized by the heat generated by the motor, and conduits connecting said chamber to a region of lower pressure, and regulating means in said conduits for minimizing the pressure differential across said rotor chamber.
  • a motor pump unit comprising: a motor housing, an annular motor stator mounted within said housing, a rotor positioned Within said stator, a cylindrical can positioned intermediate said rotor and stator to form a chamber in Which said rotor rotates, said can being sealed at both ends to hydraulically separate said rotor and said stator, a shaft operatively connected to said rotor and extending through said housing, a centrifugal pump casing spaced from said housing, said casing having an axial inlet and a radially spaced outlet, an impeller connected to said shaft and positioned Within said casing in alignment with said inlet and said outlet, means positioned intermediate said rotor and said impeller to form such a close clearance with said shaft as to limit the amount of liquid leaking along said shaft into said rotor chamber to such a small amount that substantially all the liquid that flows into said chamber is vaporized by the heat generated by the motor and conduit means connecting the interior of said rotor can to the inlet side of said pump and means positioned in said conduit
  • a motor pump unit comprising: a motor housing, an annular motor stator mounted within said housing, a rotor positioned within said stator, a cylindrical can positioned intermediate said rotor and stator to form a chamber in which said rotor rotates, said can being sealed at both ends to hydraulically separate said rotor and said stator, a shaft operatively connected to said rotor and extending through said housing, a centrifugal pump casing spaced from said housing, said casing having an axial inlet and a radially spaced outlet, an impeller connected to said shaft and positioned within said casing in alignment with said inlet and said outlet, first bearing housing surrounding said shaft and positioned intermediate said motor housing and said casing, said first bearing housing forming the rear cover of said casing and a front cover of said motor housing, a second bearing housing surrounding said shaft and positioned at the other end of said rotor, said second bearing housing forming the rear cover of said motor housing, bushings mounted on said shaft and positioned to form such a close clearance with

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
US129099A 1961-08-03 1961-08-03 Canned motor pump Expired - Lifetime US3128712A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US129099A US3128712A (en) 1961-08-03 1961-08-03 Canned motor pump
GB28482/62A GB935585A (en) 1961-08-03 1962-07-24 Improved electric motor and pump unit
CH924662A CH383170A (fr) 1961-08-03 1962-08-02 Groupe moteur électrique-pompe
DE19621453711 DE1453711A1 (de) 1961-08-03 1962-08-03 Elektromotor-Pumpenaggregat
BE621060A BE621060A (enrdf_load_stackoverflow) 1961-08-03 1962-08-03

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US129099A US3128712A (en) 1961-08-03 1961-08-03 Canned motor pump

Publications (1)

Publication Number Publication Date
US3128712A true US3128712A (en) 1964-04-14

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ID=22438447

Family Applications (1)

Application Number Title Priority Date Filing Date
US129099A Expired - Lifetime US3128712A (en) 1961-08-03 1961-08-03 Canned motor pump

Country Status (5)

Country Link
US (1) US3128712A (enrdf_load_stackoverflow)
BE (1) BE621060A (enrdf_load_stackoverflow)
CH (1) CH383170A (enrdf_load_stackoverflow)
DE (1) DE1453711A1 (enrdf_load_stackoverflow)
GB (1) GB935585A (enrdf_load_stackoverflow)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3302583A (en) * 1964-02-07 1967-02-07 Conch Int Methane Ltd Submersible pumps
US3444403A (en) * 1966-05-31 1969-05-13 Westinghouse Electric Corp Submersible motor with stator liner support
US3487457A (en) * 1967-05-10 1969-12-30 Drouard Moteurs Electric motor having an airgap sleeve
US3663848A (en) * 1970-02-11 1972-05-16 Kalman Nagy Lehoczky High-speed alternating current generators
US3727085A (en) * 1971-09-30 1973-04-10 Gen Dynamics Corp Electric motor with facility for liquid cooling
US4065231A (en) * 1975-01-27 1977-12-27 Litzenberg David P Motor driven pump
US4585966A (en) * 1983-10-20 1986-04-29 Mitsubishi Denki Kabushiki Kaisha Submerged electric motor
JPS61176950U (enrdf_load_stackoverflow) * 1985-04-24 1986-11-05
DE4208829A1 (de) * 1992-03-19 1993-11-18 Wilo Gmbh Spaltrohrpumpe
US20110044831A1 (en) * 2008-05-06 2011-02-24 Christopher E Cunningham Motor with high pressure rated can
US20110052432A1 (en) * 2008-05-06 2011-03-03 Cunningham Christopher E Pump with magnetic bearings
US20140054992A1 (en) * 2011-03-23 2014-02-27 Kawasaki Jukogyo Kabushiki Kaisha Canned type rotating electrical machine
US20160380514A1 (en) * 2015-02-23 2016-12-29 ALMOTT, Ltd. Brushless electrical machine with air cooling
CN106460813A (zh) * 2014-05-30 2017-02-22 派克汉尼芬公司 集成的位移控制泵
US9887603B2 (en) * 2011-12-23 2018-02-06 Grundfos Holding A/S Wet-running centrifugal pump
US20190178258A1 (en) * 2015-10-22 2019-06-13 Liberty Pumps Inc. Shaft seals and liquid pump comprising same
CN112469901A (zh) * 2018-07-11 2021-03-09 翰昂汽车零部件德国有限公司 水泵
US12173721B2 (en) * 2021-12-13 2024-12-24 Championx Llc Bearing assemblies, apparatuses, devices, systems, and methods including bearings
CN119210035A (zh) * 2024-10-25 2024-12-27 比亚迪股份有限公司 驱动装置、驱动总成、车辆以及驱动装置的控制方法

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3804602A1 (de) * 1988-02-13 1989-08-24 Klein Schanzlin & Becker Ag Explosionsgeschuetzter spaltrohrmotor
US5591016A (en) * 1994-11-30 1997-01-07 Nikkiso Co., Ltd. Multistage canned motor pump having a thrust balancing disk
GB2357377A (en) * 1999-12-13 2001-06-20 Delphi Tech Inc Cooling a combined pump and electric generator
FR3126738A1 (fr) * 2021-09-03 2023-03-10 Optimex Groupe motopompe electrique, procede de fabrication et procede d’installation d’un tel groupe motopompe

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2741990A (en) * 1952-11-26 1956-04-17 Howard T White Motor driven pumps
US2963980A (en) * 1957-05-03 1960-12-13 Fostoria Corp Fluid take off connections for motor driven pumps and the like
US2986905A (en) * 1960-04-15 1961-06-06 Vilter Mfg Co Refrigerating system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2741990A (en) * 1952-11-26 1956-04-17 Howard T White Motor driven pumps
US2963980A (en) * 1957-05-03 1960-12-13 Fostoria Corp Fluid take off connections for motor driven pumps and the like
US2986905A (en) * 1960-04-15 1961-06-06 Vilter Mfg Co Refrigerating system

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3302583A (en) * 1964-02-07 1967-02-07 Conch Int Methane Ltd Submersible pumps
US3444403A (en) * 1966-05-31 1969-05-13 Westinghouse Electric Corp Submersible motor with stator liner support
US3487457A (en) * 1967-05-10 1969-12-30 Drouard Moteurs Electric motor having an airgap sleeve
US3663848A (en) * 1970-02-11 1972-05-16 Kalman Nagy Lehoczky High-speed alternating current generators
US3727085A (en) * 1971-09-30 1973-04-10 Gen Dynamics Corp Electric motor with facility for liquid cooling
US4065231A (en) * 1975-01-27 1977-12-27 Litzenberg David P Motor driven pump
US4115038A (en) * 1975-01-27 1978-09-19 Litzenberg David P Motor driven pump
US4585966A (en) * 1983-10-20 1986-04-29 Mitsubishi Denki Kabushiki Kaisha Submerged electric motor
JPS61176950U (enrdf_load_stackoverflow) * 1985-04-24 1986-11-05
DE4208829A1 (de) * 1992-03-19 1993-11-18 Wilo Gmbh Spaltrohrpumpe
US20110058966A1 (en) * 2008-05-05 2011-03-10 Cunningham Christopher E Flushing system
US20110044831A1 (en) * 2008-05-06 2011-02-24 Christopher E Cunningham Motor with high pressure rated can
US20110052432A1 (en) * 2008-05-06 2011-03-03 Cunningham Christopher E Pump with magnetic bearings
US20110058965A1 (en) * 2008-05-06 2011-03-10 Cunningham Christopher E In-line flow mixer
US9601964B2 (en) 2008-05-06 2017-03-21 Fmc Technologies, Inc. In-line flow mixer
US8696331B2 (en) 2008-05-06 2014-04-15 Fmc Technologies, Inc. Pump with magnetic bearings
US8777596B2 (en) 2008-05-06 2014-07-15 Fmc Technologies, Inc. Flushing system
US20140054992A1 (en) * 2011-03-23 2014-02-27 Kawasaki Jukogyo Kabushiki Kaisha Canned type rotating electrical machine
US9438081B2 (en) * 2011-03-23 2016-09-06 Kawasaki Jukogyo Kabushiki Kaisha Canned type rotating electrical machine
US9887603B2 (en) * 2011-12-23 2018-02-06 Grundfos Holding A/S Wet-running centrifugal pump
CN106460813A (zh) * 2014-05-30 2017-02-22 派克汉尼芬公司 集成的位移控制泵
US20170184092A1 (en) * 2014-05-30 2017-06-29 Parker-Hannifin Corporation Integrated displacement controlled pump
CN106460813B (zh) * 2014-05-30 2020-05-19 派克汉尼芬公司 集成的位移控制泵
US20160380514A1 (en) * 2015-02-23 2016-12-29 ALMOTT, Ltd. Brushless electrical machine with air cooling
US20190178258A1 (en) * 2015-10-22 2019-06-13 Liberty Pumps Inc. Shaft seals and liquid pump comprising same
US11629728B2 (en) * 2015-10-22 2023-04-18 Liberty Pumps, Inc. Shaft seals and liquid pump comprising same
CN112469901A (zh) * 2018-07-11 2021-03-09 翰昂汽车零部件德国有限公司 水泵
US12173721B2 (en) * 2021-12-13 2024-12-24 Championx Llc Bearing assemblies, apparatuses, devices, systems, and methods including bearings
CN119210035A (zh) * 2024-10-25 2024-12-27 比亚迪股份有限公司 驱动装置、驱动总成、车辆以及驱动装置的控制方法

Also Published As

Publication number Publication date
BE621060A (enrdf_load_stackoverflow) 1963-02-14
CH383170A (fr) 1964-10-15
GB935585A (en) 1963-08-28
DE1453711A1 (de) 1969-04-30

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